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DIRECTV and Ka (with satellite configs)

Discussion in 'DIRECTV Tips and Resources' started by Tom Robertson, Mar 13, 2007.

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  1. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    This series of posts is meant to detail DIRECTV’s long history with the Ka band, describe the various DIRECTV Ka satellites, compare Ka with Ku, and then provide some links into where to find more information from the FCC and FAA.

    Ka Timeline Summary
    DIRECTV, perhaps with others, proposed to the FCC in 1993 the usage of Ka band frequencies for direct to home usage. With the launches of S1, D8, S2, and D9s, 12 years later, we are enjoying the results of many years of waiting for FCC approval, satellite design and equipment design, and satellite launch. With two more Ka only satellites to be launched soon, D10 and D11, we will have many HD nationwide channels which will also reach into Alaska and Hawaii.

    Some of the major milestones along this journey:

    Dec. 1993: Hughes requests Launch and Operate Authority (LOA) for Ka satellite operations at 99° and 101° (and others) as a part of the Hughes Network Spaceway system. I’ve been able to only find minimal information on these requests online: FCC LOA application file

    Sept. 1995: PanAmSat makes similar requests for Ka BSS and FSS at 67° as call sign S2191. FSS license is transferred to 103° and to HNS (both were subsidiaries of Hughes Electronics at the time) in March 2003 and then withdrew BSS 67° in January 2004. FCC LOA application file

    May 1997: FCC awards licenses for Ka to 13 companies.
    Award summary
    Echostar Grant
    Hughes Grant

    June 2000: Based on feedback and usage information worldwide, the FCC modifies and standardizes the Ka band frequency usage for satellite operators. FCC Word document or FCC text file (Set the downlink frequencies to 18.3-18.8GHz and 19.7-20.2GHz)

    Dec. 2001: Echostar and DIRECTV merger attempt. Declined by FCC in October 2002.

    March 2003: PanAmSat transferred license for 103° to Hughes Network Systems: FCC File

    March 2004
    : Hughes Electronics renamed DIRECTV Group.

    End of May 2004: WSJ and other news agencies indicate that Hughes cancels the Hughes Network, broadband from space. DIRECTV releases a press statement that the Spaceway satellites will continue to be used for video and broadband: Press Announcment

    June, 2004
    : Modification request to D8 to replace D2 and merge an existing Ka license into one hybrid satellite: FCC File Application details(pdf)

    Sept. 2004: DIRECTV announces plans for HD via S1/S2 and D10/D11. Also, the HR10-250 is launched: Press Announcement

    January 2005: At CES, DIRECTV demonstrates MPEG4 compressed HD via satellite: Press Announcement. Thanks to Alan Gordon for pointing this out.

    April 2005: Spaceway 1 Launched

    May 2005: D8 Launched

    June 2005: D8 becomes the first operational DIRECTV Ka satellite; operating at 101°, just before the license grant milestone would have expired. (I can’t believe FCC wouldn’t have extended the milestone had the launch been delayed. Every previous milestone had been clearly met and DIRECTV obviously had the satellite ready to go.) D8 uses Ka frequencies for uplink of HD locals to regional and national broadcast centers.

    Nov. 2005: Mod to D9s to have Ka added: FCC Modfication request record

    Nov. 2005: Hughes Network Systems sold to SkyTerra, completed January 2006. Ultimately Spaceway 3 went to SkyTerra.

    Nov. 2005: Spaceway 2 Launched

    Oct. 2006: D9s Launched

    2007: D10 and D11 to be launched

    [Disclaimers] All these posts contain data from public records as noted and linked. Most are from the FCC, but also the companies' press releases or websites.

    All commentary is mine. No representation as to information from DIRECTV, Boeing, Space Systems/Loral, or any other named corporate entity is implied unless directly noted.

    At the time of writing, I work for none of the companies listed in these postings, nor have any impending relationship of such nature.

    [/Disclaimers]
     
  2. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    D8 and D9s started as two satellites each. A replacement for an existing DBS satellite (D1 or D2) and as a separate Ka band license. They were merged into hybrid satellites by the addition (or changeout) of Ka transponders onto the already under construction Space Systems/Loral 1300 satellites. Their Ka role is solely for backhauling HD locals to the national broadcast centers in Colorado and Los Angeles. Given how different they are in configuration, they have been given their own postings.

    D8 Stats
    Location:101.75°
    Callsigns: S2632 (D2 replacement) and S2132 (Ka)
    Launch: May 22, 2005 International Launch Services
    Start of operations: June 23, 2005 (two days before deadline in the FCC conditions of authorization for the Ka license.)

    D8 Ka Configuration

    FCC MOD request file
    Application details (see pages 9-22 for configuration)
    Specialized wideband spotbeams: eight 250mhz wide uplinks and four 500mhz wide down.
    Uplinks from 4 regional broadcast facilities:
    Seattle, WA
    Castle Rock, CO
    Atlanta, GA,
    New York, NY

    Downlinks to two broadcast centers:
    Kansas City, MO
    Los Angeles, CA

    Each downlink is an 85W TWTA.

    D8 DBS Configuration
    FCC Replacement (RPL) request file
    Application details (see pages 7-15)
    D8's transponders are purely nationwide, including Alaska and Hawaii.
    16 nationwide odd numbered transponders, 12.2-12.7ghz. D8 also has 6 nationwide even numbered transponders should it be moved to either the 110° or 119° slots as a replacement satellite.

    All transponders are dual 113W DLCTs per channel giving a total 226W.

    Other Links
    FCC grant
    DIRECTV letter to FCC of start of operations for D8, S1, S2
     

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  3. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    D9s is a hybrid, hybrid configuration satellite. Not only does it have spotbeam and nationwide, including Alaska and Hawaii DBS transponders, it also has Ka wideband spotbeam capabilties. D9s is built upon a Space Systems/Loral 1300 bus.

    D9s Stats
    Location: 101.10°
    Callsigns: S2669(D1 replacement), S2679 (failed for paperwork reasons), S2689 (Ka)
    Launch: October 13, 2006 Arianespace
    Start of operations: December 18, 2006

    D9s Ka Configuration
    FCC LOA request record
    Application details (see pages 5- 11)
    Two 500mhz wideband transponders

    Uplink regional broadcast facilities:
    Boise, ID
    Las Angeles, CA

    Downlink to two broadcast centers (for re-uplinking to 99° and 103°)
    Tucson, AZ (Typically the Left Hand Circular Polarized uplinks.)
    Minneapolis, MN (Typically RHCP)

    Each transponder has one 85W TWTA.

    D9s DBS Configuration
    FCC Replacement (RPL) request file
    Application details (see pages A-7 thru A-13)
    32 DBS channels for uplink
    16 DBS even numbered channels as 10 (or up to 12 even and 1 odd) nationwide transponders and 42 spotbeam transponders down (had been 44 before Ka were installed)
    52 total Ku transponders, 12.2-12.7ghz, replaces DIRECTV 1, redundancy for D4s
    8PSK modulation
    Each nationwide transponder is a triple combined 150W DLCTs

    Other link
    FCC grant
     

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  4. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    Spaceway 1 and 2 (S1/S2) were originally purchased by Hughes Network Systems to provide advanced broadband internet services to the home and business. The Boeing 702 bus-based satellites were unique, having on-board internet routing capabilities, sending traffic from one uplink to the appropriate downlink without having to first downlink the data to a land-based network facility. The satellites were meant to be deployed in a whole constellation of similar satellites, linked to each other in a mesh arrangement. A whole Internet network in space, further reducing the need for land-based facilities. Alas the network as designed was too expensive to the end consumer as compared to the prices of DSL and cable.

    The two satellites are also very unique in that they do not use traditional transponders to downlink data. Instead S1, S2, (and their brother S3) each use a 1,500 element phased array to generate their downlinks as needed. The phased array is capable of creating spotbeams as small as .5° or as large as full nationwide coverage. Other unique advanced features included highly variable beam strength that automatically adjust to compensate for weather conditions in various parts of the country.

    In 2004, DIRECTV repurposed S1 and S2 for a couple reasons: 1) to better support video in addition to the broadband, 2) (my guess) to fully utilize the Ka licensed bandwidth before losing their licenses for failure to meet critical milestones.

    S1/S2 repurpose announcement: September 8, 2004 Press Announcement

    In 2001 FCC modification requests (MOD) were filed updating the original S1/S2 licenses. The MODs were based upon the new Boeing 702 satellite bus and the phased array for downlink spotbeams. In 2004 those MODs where withdrawn and re-filed to reflect the repurposing. Based on differences between those MOD filings, here is my best estimate summary of those changes:
    Addition of downlinks in the Ka B-band 18.3-18.8GHz frequency range (as two 165mhz downlinks within the 500mhz bandwidth for backhauling purposes.)
    Addition of a potter horn for the transmission of the new B-band backhauling signals.
    A whole section describing non-processor mode operation where the satellite’s A-band (the phased array) retransmits what goes up straight back down its downlinks. A traditional “bent-pipe” mode of operation (tho still with a very non-traditional phased array). In this mode, there are 8 “channels” 65mhz wide up and down. Does this mean the receivers are now looking at 62.5mhz wide channels for MPEG4 locals?

    S1/S2 Stats
    S1 location: 102.80 (was originally proposed to be 103.05)
    S2 location: 99.20 (was originally proposed to be 99.05)
    S1 Launch: April 26, 2005, SeaLaunch Press Announcement
    S1 start of operations: October 20, 2005 (Boeing turned over October 10, 2005)
    S2 Launch: November 16, 2005 Press Announcement
    S2 start of operations: April 14, 2006

    Phased Array
    The phased array is so flexible that current operating characteristics are not discernible from the FCC request filings. While many sample configurations are presented, they do not seem to actually describe the current operations.

    Known details:
    1500 elements
    Operates in the Ka A-band 19.7-20.2GHz downlink frequency range
    Can theoretically do at least one nationwide beam
    Or up to 112 spotbeams

    B-band potter horn
    Operates in the Ka B-band 18.3-18.8GHz downlink frequency range
    15W TWTA
    4 Transponders?
    Transponder bandwidth 165mhz

    FCC and other links
    2001 First MOD filed to change from Boeing 601 to 702 bus, utilize phase array, for locations 99° and 101°. Withdrawn June 2004
    FCC MOD record
    Application (see pages 5-9, pdf)

    S1 2004 Mod (Approved): FCC MOD record
    S1 2004 Mod details: Application (see pages 9-19, pdf) (Be ready for a headache.)

    S1 mod for location: FCC MOD record
    S1 mod location grant (with application): FCC grant (pdf)
    S2 Mod for location: FCC MOD record
    S2 location grant (with application): FCC grant (pdf)

    Boeing hi-rez image of the Spaceway satellites (prior to potter horn addition.)
     

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  5. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    D10 and D11 (with ground spare, D12) are the latest DIRECTV Ka satellites. Serving both nationwide (which includes Alaska and Hawaii) and 49 spotbeam locations each, these Ka only satellites are built upon the Boeing 702 Bus.

    Ka licensing configuration
    Downlink in the Ka B-band 18.3-18.8GHz frequency range
    40mhz channel spacing (36mhz usable.)
    14 Nationwide transponders
    10 spotbeam transponder frequencies
    49 total spotbeams.​

    Satellite payload configuration
    National/Alaska
    28 active TWTAs [2 per transponder]
    8 spare TWTAs

    National/Hawaii
    4 active TWTAs
    4 spare TWTAs

    Spot
    55 Active TWTAs
    15 Spare TWTAs

    Reflectors
    4 spotbeam transmit reflectors
    2 Nationwide transmit reflectors
    36mhz usable per channel (roughly 7x a UHF/VHF band channel)
    Dual amplifier TWTAs 130w each, 260W combined
    Spot single amplifier TWTA 70W each

    Contractual launch vehicle requirements
    From the contract:
    Boeing Factsheet

    FCC links
    D10 FCC LOA request record
    D10 details (see pages 7-14)
    D10 grant

    D11 FCC LOA request record
    D11 Appliation details

    D10 and D11 milestone documents includes the contract with Boeing for D10/D11/D12 (redacted in the FCC public database)
     

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  6. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    BSS Frequency Range Usage
    The next big thing is reusing the current DBS uplink frequencies in a downlink mode. Right now a very usable frequency range for downlinks to the home are only used as the standard uplink frequencies for the original DBS downlinks. Directv, along with others have determined that using this frequency range for downlinks will further increase the bandwidth available for satellite operators. The FCC has several requests before it, and the ITU has announced that April 1, 2007 (hmmm, interesting date), those frequencies will be made available for use in the US. But as of this writing, the FCC has not awarded any license nor published a plan for licensing like they did for Ka in 1997 and modified in 2001. (At least I haven’t found one yet.)

    The downlink frequency range would likely be 17.3-17.7GHz in the US and 17.3-17.8GHz to Latin America (including Mexico.)

    Sample DIRECTV application for BSS-99: http://svartifoss2.fcc.gov/servlet/ib.page.FetchAttachment?attachment_key=-115964

    Questions arise should this come to pass:
    What changes will be needed to the current ODU?
    Will the new frequency range fit on the current coax or will SWM be required?
    New receivers too?

    D13, Callsign S2693
    While not Ka-band, it is part of the immediate DIRECTV future. Requests have been filed and approved with the FCC for replacing D5 at the 110° orbital slot with a new satellite, D13. The milestone requirements for D13 include:
    Contract to build: by November 16, 2007
    Build completion: by November 16, 2010
    Launch and operation: by November 16, 2012.

    While DIRECTV is licensed for only 3 DBS channels at that location, to allow flexibility and redundancy across their satellite fleet, D13 will be built to handle all 16 even DBS channels. (Ku band)

    I'm sure we'll see a press release this year announcing the contract award.

    FCC RPL record
    FCC Grant
     
  7. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    Commentary
    Thank goodness, DIRECTV has very good lawyers and engineers putting their FCC requests together. They are very well arranged and consistent in form. That made them so very much easier to read than other companies’ requests…

    I’m constantly amazed at how much forethought has gone into this by DIRECTV. Just based on the FCC filings alone, this has been a 14 year process so far! And still more to come. There are also notes and comments that DIRECTV has been one of the major leaders getting the FCC to endorse the usage of the Ka bandwidth. And I’m sure looking forward to more HD because of their efforts.

    C, Ku, Ka
    Unlike C band transponders, Ku and Ka do not have standardized transponder frequencies (although, DBS usage of Ku has been standardized by the FCC and ITU). Outside of the dbs satellites, to use a Ku transponder, an engineer needs to verify (and double check) the specific frequencies for that particular satellite.

    Ka is even more flexible. D8 and D9s were always surprising to me in that they only had a very few Ka transponders. What I did not realize is that each transponder’s signal is 250mhz wide. While not very useful for dbs purposes, they are quite useful for backhauling OTA signals around the country ultimately for uplink to the spotbeams from the satellites at 99° or 103°.

    Ka satellite locations can operate with 2 degrees of separation, narrower than the 4 degree necessary for Ku.

    Typical Ka dbs licenses allow two 500 mhz ranges of downlinking: 19.7-20.2 GHz (A-band) and 18.3-18.8GHz (B-band) as well as three more of uplinking. Ku licenses allow one 500 mhz range each.

    Directv standard Ku transponders, numbered 1-32, are 29mhz wide with 24mhz usable. For D10 and D11, Ka transponders are numbered 1-24, and are 40mhz wide with 36mhz usable. S1 and S2 can be operated as eight transponders 62.5mhz wide.

    Ku transponders alternate polarity and are offset in frequency much like two courses of bricks. Ka transponders also alternate polarity, but operate on the exact same frequency for adjacent even and odd transponders.

    Because of the smaller guard frequenies between transponder channels and the overlapping structure of Ka vs. the offset used by Ku, Ka gives about 10% more usable bandwidth.
    Ku usable bandwidth from 500mhz available is 384mhz.
    Ka usable bandwidth from 500mhz available is 432mhz.
     
  8. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    Satellite transponder technologies
    TWTA – Traveling Wave Tube Amplifier
    DLCT – Direct radiating Linearized Channel amplified TWT

    FCC satellite request form types
    LOA – FCC request form for Launch and Operate Authority for operating a satellite
    RPL – RCC request form to replace an existing satellite
    MOD – FCC request form to modify a previous request
    AMD – FCC request form to amend a previous request
    T/C-FCC request form to Transfer Control of a satellite to a new corporate entity

    Good FCC sites

    All these links are to the FCC's International Bureau Filing System (IBFS):
    Advanced IBFS search form for Satellite Space Station records.
    FCC IBFS Orders (actions, grants, dismissals, etc.)
    FCC IBFS welcome page (access to public notices)
    IBFS Queue report
     
  9. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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  10. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    D13's license has been surrendered since "tweener" satellite licenses have been processed (one granted, not sure about the other) that affect DIRECTV's certainty of satisfactory video service from 110°.
    To see the original page: http://svartifoss2.fcc.gov/servlet/ib.page.FetchAttachment?attachment_key=606020

    Cheers,
    Tom
     
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